20.10.036 Accessory dwelling units | Bellingham Municipal Code

20.10.036 Accessory dwelling units.

1. It is the purpose of this legislation to implement policy provisions of the city’s comprehensive plan promoting increased housing options and innovation that will help meet the needs of the many sectors of the community, including smaller households, students, millennials, baby boomers, people with disabilities, and low-income families; make more efficient use of public infrastructure and services; are within walking distance to shops, jobs, and amenities; encourage well-designed infill development; and improve the economic and social well-being of the community.

2. The director shall have the authority to approve accessory dwelling units (ADUs) which are consistent with the regulations and provisions herein.

3. Enforcement. The city retains the right (with reasonable notice) to inspect the ADU for compliance with this section.

4. Any property owner with an unpermitted ADU on its property shall be in violation of this subsection and subject to the penalties in Chapter 20.52 BMC.

5. Any property owner with an ADU on its property that is in violation of any standard in subsection (B) of this section shall be in violation of this subsection and subject to the penalties in Chapter 20.52 BMC.

1. Accessory dwelling units (ADUs) may be allowed in general use types where listed as a permitted use if they comply with the requirements listed in this section, except on property regulated by Chapter 16.80 BMC, Lake Whatcom Reservoir Regulatory Provisions.

2. An ADU shall comply with all zoning code provisions for the primary dwelling unit, including height, setbacks, floor area, accessory buildings and open space, except as provided in this section. This provision shall also apply to ancillary structures attached to a D-ADU such as garages, carports, garden sheds and workshops.

3. Applicants may request minor modifications to the development and design standards for ADUs. A minor modification is a request by the applicant to meet or exceed a particular ADU standard through the use of a technique or alternative standard not otherwise listed under the applicable requirement. Minor modifications are not variances and are not required to meet all of the criteria typically associated with a variance application. The director may grant a minor modification if the following criteria are met:

a. The site is physically constrained due to, but not limited to, unusual shape, topography, easements, existing development on site, or critical areas; or

b. The granting of the modification will not result in a development that is less compatible with adjacent neighborhood land uses; and

c. The granting of the modification will not be materially detrimental to the public welfare or injurious to other land or improvements in the vicinity and district in which the property is situated; and

d. The granting of the modification is consistent with the purpose and intent of this section; and

e. All reasonable mitigation measures for the modification have been implemented or assured.

a. The land on which the ADU is located shall not be subdivided from the land on which the primary dwelling unit is located, but the ADU may be segregated in ownership from the primary dwelling unit.

b. Owner occupancy is required for properties that include an ADU (or ADUs) in areas zoned residential single until occupancy requirements are preempted by the state law. Prior to implementation of state law, the following applies. The property owner shall submit an affidavit, approved by the director, acknowledging the owner occupancy requirement for as long as the ADU is maintained on the property or until owner occupancy requirements are preempted by the implementation of state law. The property owner shall submit the affidavit to the city prior to issuance of the building permit. The affidavit shall specify the requirements for owner occupancy and purchaser registration as follows:

i. An owner of the subject property shall reside on the premises, whether in the primary or accessory dwelling; provided, that:

(A) In the event of illness, death or other unforeseeable event which prevents the owner’s continued occupancy of the premises, the director may, upon a finding that discontinuance of the ADU would cause a hardship on the owner and/or tenants, grant a temporary suspension of this owner-occupancy requirement for a period of one year. The director may grant an extension of such suspension for one additional year, upon a finding of continued hardship.

(B) In the case of bringing an unpermitted ADU into compliance with this section, if the property on which the ADU is located complies with all of the requirements of this section except owner-occupancy, the property may continue without occupancy by the owner for the remainder of the lease(s) on the property, not to exceed one year. Thereafter, the property shall be occupied by the owner, or transferred to a different owner who will reside on the premises.

ii. Purchasers of homes with an ADU shall register with the planning and community development department within 30 days of purchase.

a. No more than two ADUs shall be permitted in conjunction with the primary dwelling unit on a single lot of record. The lot may not contain more than one primary dwelling unit. The ADUs are exempt from density limitations and may be in any configuration of attached or detached units.

b. The ADU main entrance shall have direct access to a street via a lighted pedestrian path, driveway or alley.

a. Attached and Detached ADUs. An ADU shall not exceed 1,000 square feet.

b. Attached ADUs (A-ADU). The maximum floor area in subsection (B)(6)(a) of this section does not apply when the basement of a primary dwelling unit is converted to an A-ADU and the primary dwelling unit has been on the site for at least five years.

c. Detached ADUs (D-ADU). The floor area for D-ADUs shall be calculated to include all attached ancillary space (garage, workshop, garden shed, etc.). Maximum allowed floor area limits are as follows:

i. A D-ADU with ancillary space may exceed 1,000 square feet when approved by the hearing examiner by conditional use permit pursuant to Chapter 20.16 BMC.

ii. When an oversized detached accessory building approved by conditional use permit has been on site for at least five years, conversion of said building to a D-ADU may occur without subsequent conditional use permit approval.

iii. For subsections (B)(6)(c)(i) and (ii) of this section, the floor area of the D-ADU, sans ancillary space, shall not exceed that specified in subsection (B)(6)(a) of this section.

a. Front and side-flanking yards shall comply with the zoning code provisions for the primary dwelling unit except that when the vehicular entrance to an attached garage or carport faces a street, the entrance shall be set back a minimum of 25 feet from the front property line, and 10 feet from a side flanking property line.

b. A five-foot side and rear yard setback shall be provided, measured from the property line to the foundation of the structure, except as follows:

i. When abutting an alley, there is no required side or rear yard setback from the alley.

ii. A D-ADU may be located in a rear yard and in the rear 22 feet of an interior side yard, provided:

(A) If a D-ADU is to be located less than five feet from any common property line, a joint agreement with the adjoining property owner(s) must be executed and recorded with the Whatcom County auditor’s office and thereafter filed with the city prior to issuance of building permit; or

(B) If site characteristics warrant such that, in the opinion of the director, impacts to abutting property would be negligible due to, but not limited to, one or more of the following:

(1) The existing use and development pattern on abutting property.

(2) Minimal disruption of solar access to outdoor recreation or garden space on abutting property compared to what may otherwise occur with the application of standard development regulations.

(3) Site characteristics such as building a D-ADU downslope from abutting property.

(4) Conversion of a detached accessory building that is at least five years old and has had no additions within the required side or rear yard within that time period.

(5) Any minor modification from standard development regulations requested pursuant to this subsection (B)(7)(b)(ii) shall be processed as a request for minor modification pursuant to subsection (B)(3) of this section.

c. A minimum six feet of separation is required between the primary dwelling unit and a D-ADU.

8. Building Height for D-ADUs. A D-ADU shall be no higher than 24 feet under BMC 20.08.020, height definition No. 1 or 12 feet under height definition No. 2.

9. Parking. Parking required for an ADU is in addition to that required for the primary dwelling unit.

a. One on-site parking stall is required for an ADU, except as follows:

i. No parking is required when improved public street parking is available on at least one side of the block face whereon the ADU is proposed, on-street parking is constructed, or the ADU is within one-half mile walking distance to a major transit route.

ii. The director may waive parking based on the applicant’s demonstration of site-specific factors that justify a lower standard. Any request for a parking waiver shall be processed as a request for minor modification pursuant to subsection (B)(3) of this section.

b. Parking stalls shall be at least nine feet by 18 feet.

c. Parking shall not be located in required front or side street setbacks. Parking in the front portion of the lot shall be discouraged.

d. If the lot abuts an alley or private access easement, parking shall be accessed from said facility except when the director determines that such access is impractical or environmentally constrained. Any request to forgo alley access shall be processed as a request for minor modification pursuant to subsection (B)(3) of this section.

e. Parking accessed from a street or lane shall be limited to one driveway per frontage with a maximum width of 20 feet.

10. Privacy. Where practical, locate and design the ADU to minimize disruption of privacy and outdoor activities on adjacent properties. Strategies to accomplish this include, but are not limited to:

a. Stagger windows and doors to not align with such features on abutting properties.

b. Avoid upper level windows, entries and decks that face common property lines to reduce overlook of a neighboring property.

c. Install landscaping as necessary to provide for the privacy and screening of abutting property.

11. Repealed by Ord. 2023-08-022.

a. Water, Sewer, Storm. A primary dwelling unit and ADU(s) may have a shared water service to a water system, a shared sewer service to a sewer system and a shared storm service to a stormwater management system, in which case the primary dwelling unit will be responsible for all billing and maintenance of the services. Separate and independent services from each building may be required to meet the city’s adopted plumbing code. In all cases, the water service shutoff must be accessible to occupants of all units.

b. Electrical. A primary dwelling unit and ADU(s) are permitted to have one shared electrical service if a single building or separate electrical services if separate buildings. A separate meter is permitted to serve an ADU, subject to compliance with the city’s adopted electrical code. A single main service panel may be allowed; provided, that occupants of all dwelling units have access to the overcurrent devices supplying their occupancy.

c. Gas. A primary dwelling unit and ADU(s) may share natural gas services. An accessible shut-off valve must be upstream of the gas meter, on the exterior of the structure(s).

d. Any utility lines being installed or altered must have their connections inspected as part of the building permit process.

13. Compliance With Applicable Codes. ADUs shall comply with all standards for health and life safety as set forth in the International Building Code, International Residential Code, Uniform Plumbing Code, National Electrical Code, International Mechanical Code, International Fire Code, and Washington State Energy Code as each code is adopted by the city; and any other applicable codes or regulations, except as provided in this section.

14. Accessibility. To encourage the development of housing units for people with disabilities, the director may allow reasonable deviation from the stated requirements to install features that facilitate accessibility. Such facilities shall be in conformance with the city adopted building code.

1. Application may be made for any accessory dwelling unit existing prior to January 1, 1995, to become legally permitted, pursuant to the provisions of this section. Whether an ADU permit is approved or denied, the owner of any nonpermitted unit shall be subject to the penalties provided in this code.

2. An application to legalize an existing ADU shall include an application for an ADU permit and a building permit application, showing changes made to the primary dwelling unit or detached accessory building to accommodate the ADU. Approval shall be consistent with the ADU regulations and process outlined in this section. The ADU shall be reviewed using the current editions of building codes in place at the time its owner brings the unit forward for permit.

3. Nothing in this section shall require that the city permit existing ADUs that are determined to be dangerous.

D. Permitting Process. An ADU is required to obtain approval following the procedures established in Chapter 21.10 BMC. [Ord. 2023-08-022 § 2 (Exh. A); Ord. 2021-12-053 § 3; Ord. 2018-05-009 § 5].